/* =========================================
   1. CSS 변수 설정 (Light/Dark Mode)
   ========================================= */
:root {
    /* 라이트 모드 (기본) */
    --bg-color: #f9f9f9;
    --container-bg: #ffffff;
    --text-color: #333333;
    --text-secondary: #555555;
    --text-muted: #888888;
    --accent-color: #0066cc;
    --border-color: #eeeeee;
    --nav-bg: rgba(255, 255, 255, 0.95);
    --shadow-color: rgba(0,0,0,0.05);
    --link-btn-bg: #f8f8f8;
    --tag-red: #e74c3c;
    --tag-blue: #3498db;
    --tag-green: #2ecc71;
    --tag-gray: #8d8d8d;
}

/* 다크 모드 오버라이드 */
body.dark-mode {
    --bg-color: #121212;
    --container-bg: #1e1e1e;
    --text-color: #e0e0e0;
    --text-secondary: #b0b0b0;
    --text-muted: #999999;
    --accent-color: #66b3ff; 
    --border-color: #333333;
    --nav-bg: rgba(30, 30, 30, 0.95);
    --shadow-color: rgba(0,0,0,0.3);
    --link-btn-bg: #2c2c2c;
    /* 태그 색상은 다크모드에서도 가독성이 좋아 그대로 둡니다 */
}

/* =========================================
   기본 스타일
   ========================================= */
body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
    line-height: 1.6;
    color: var(--text-color);
    margin: 0;
    padding: 0;
    background-color: var(--bg-color);
    transition: background-color 0.3s, color 0.3s;
    padding-top: 60px; /* 내비게이션 바 높이만큼 여백 */
}

a {
    color: var(--accent-color);
    text-decoration: none;
}

a:hover {
    text-decoration: underline;
}

h1, h2, h3, h4 {
    margin-top: 0;
    color: var(--text-color) !important; /* 강제 적용 */
}

h2 {
    font-size: 1.5rem;
    border-bottom: 2px solid var(--border-color);
    padding-bottom: 10px;
    margin-bottom: 25px;
    margin-top: 40px;
}

h3.pub-category {
    font-size: 1.2rem;
    color: var(--text-secondary);
    margin-top: 40px;
    margin-bottom: 20px;
    border-left: 4px solid var(--accent-color);
    padding-left: 10px;
}

/* 메인 컨테이너 */
.container {
    max-width: 900px;
    margin: 40px auto;
    background: var(--container-bg);
    box-shadow: 0 0 20px var(--shadow-color);
    padding: 50px;
    transition: background 0.3s, box-shadow 0.3s;
}

hr {
    border: 0;
    border-top: 1px solid var(--border-color);
    margin: 50px 0;
}

footer {
    margin-top: 80px;
    text-align: center;
    color: var(--text-muted);
    font-size: 0.8rem;
}

/* =========================================
   상단 내비게이션 바 (New)
   ========================================= */
#navbar {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 60px;
    background-color: var(--nav-bg);
    backdrop-filter: blur(10px);
    box-shadow: 0 2px 10px var(--shadow-color);
    z-index: 1000;
    display: flex;
    justify-content: center;
    align-items: center;
    transition: background-color 0.3s;
}

.nav-content {
    width: 100%;
    max-width: 900px;
    padding: 0 20px;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.nav-links {
    list-style: none;
    display: flex;
    gap: 20px;
    padding: 0;
    margin: 0;
}

.nav-links li a {
    text-decoration: none;
    color: var(--text-secondary);
    font-weight: 500;
    font-size: 0.95rem;
    transition: color 0.2s;
}

.nav-links li a:hover, .nav-links li a.active {
    color: var(--accent-color);
}

.nav-home {
    font-weight: bold !important;
    color: var(--text-color) !important;
    margin-right: 10px;
}

/* 스크롤 시 섹션 위치 보정 */
section {
    scroll-margin-top: 80px;
}

/* 다크모드 토글 버튼 */
#theme-toggle {
    background: none;
    border: none;
    color: var(--text-color);
    font-size: 1.2rem;
    cursor: pointer;
    padding: 5px;
    transition: transform 0.2s;
}

#theme-toggle:hover {
    transform: scale(1.1);
    color: var(--accent-color);
}

/* =========================================
   상단 프로필 (Profile)
   ========================================= */
.profile-header {
    display: flex;
    gap: 40px;
    align-items: flex-start;
    margin-bottom: 40px;
}

.profile-img {
    flex-shrink: 0;
}

.profile-img img {
    width: 180px;
    height: 180px;
    border-radius: 50%;
    object-fit: cover;
    border: 1px solid var(--border-color);
    box-shadow: 0 4px 6px var(--shadow-color);
}

/* 다크모드에서 이미지 눈부심 방지 */
body.dark-mode .profile-img img {
    opacity: 0.9;
    border-color: #444;
}

.profile-info h1 {
    font-size: 2.2rem;
    margin-bottom: 15px;
    color: var(--text-color);
}

.bio p {
    font-size: 1rem;
    margin-bottom: 10px;
    color: var(--text-secondary);
    line-height: 1.6;
}

.contact-links {
    margin-top: 20px;
}

.contact-item {
    font-size: 0.95rem;
    color: var(--text-secondary);
    margin-bottom: 10px;
}

.contact-item i {
    margin-right: 8px;
    color: var(--text-muted);
}

.link-buttons {
    display: flex;
    flex-wrap: wrap;
    gap: 10px;
}

.link-buttons a {
    display: inline-block;
    padding: 4px 12px;
    border: 1px solid var(--border-color);
    border-radius: 20px;
    background: var(--link-btn-bg);
    color: var(--text-color);
    font-size: 0.9rem;
    transition: all 0.2s;
}

.link-buttons a i {
    margin-right: 6px;
    font-size: 0.95em;
}

.link-buttons a:hover {
    background: var(--accent-color);
    color: #fff;
    border-color: var(--accent-color);
    text-decoration: none;
}

/* =========================================
   뉴스 섹션 (News)
   ========================================= */
.news-list {
    list-style: none;
    padding: 0;
}
.news-list li {
    margin-bottom: 12px;
    display: flex;
}
.news-list .date {
    font-weight: bold;
    min-width: 100px;
    color: var(--text-secondary);
}
.news-list .desc a {
    color: var(--accent-color);
}

/* =========================================
   학력 섹션 (Education)
   ========================================= */
.edu-list {
    list-style: none;
    padding: 0;
}

.edu-list li {
    margin-bottom: 40px;
}

.edu-header {
    display: flex;
    justify-content: space-between;
    align-items: baseline;
    margin-bottom: 8px;
}

.edu-title {
    font-weight: bold;
    font-size: 1.1rem;
    color: var(--text-color) !important;
    padding-right: 15px;
}

.edu-date {
    font-weight: bold;
    color: var(--text-muted); 
    font-size: 0.95rem;
    flex-shrink: 0;
}

.edu-desc {
    color: var(--text-secondary);
    font-size: 0.95rem;
    margin-bottom: 4px;
    line-height: 1.5;
}
.edu-desc a {
    color: var(--text-color) !important;
}
body.dark-mode .edu-desc a {
    color: var(--text-color) !important;
}

/* =========================================
   경력 섹션 (Work Experience)
   ========================================= */
.work-list {
    list-style: none;
    padding: 0;
}

.work-list > li {
    margin-bottom: 40px;
}

.work-header {
    display: flex;
    justify-content: space-between;
    align-items: baseline;
    margin-bottom: 5px;
}

.work-org {
    font-weight: bold;
    font-size: 1.1rem;
    color: var(--text-color) !important;
}
.work-org a {
    color: var(--text-color) !important;
}

.location {
    font-weight: normal;
    font-size: 0.9rem;
    color: var(--text-muted);
    margin-left: 5px;
}

.work-date {
    font-weight: bold;
    color: var(--text-muted);
    font-size: 0.95rem;
    flex-shrink: 0;
}

.work-role {
    font-weight: 600;
    color: var(--text-secondary);
    font-size: 1rem;
    margin-bottom: 10px;
}

.work-desc {
    padding-left: 20px;
    margin: 0;
}

.work-desc li {
    margin-bottom: 5px;
    font-size: 0.95rem;
    color: var(--text-secondary);
    line-height: 1.5;
    list-style-type: disc;
}

/* =========================================
   출판물 섹션 & 필터
   ========================================= */
#filter-container {
    margin-bottom: 20px;
    padding-bottom: 10px;
    border-bottom: 1px solid var(--border-color);
}

.filter-btn {
    margin-right: 15px;
    cursor: pointer;
    font-size: 0.95rem;
    color: var(--text-muted);
    font-weight: 500;
    transition: all 0.2s ease;
    display: inline-block;
    margin-bottom: 5px;
}

.filter-btn:hover {
    color: var(--text-color);
    text-decoration: underline;
}

.filter-btn.active {
    color: var(--accent-color);
    font-weight: bold;
}

.publication-item {
    display: flex;
    margin-bottom: 35px;
    gap: 25px;
    align-items: flex-start;
}

.pub-thumb {
    flex-shrink: 0;
}

/* [수정됨] 이미지 크기를 260px로 확대 */
.pub-thumb img {
    width: 260px;
    height: auto;
    border: 1px solid var(--border-color);
    border-radius: 4px;
    display: block;
    box-shadow: 0 2px 4px var(--shadow-color);
}

body.dark-mode .pub-thumb img {
    border-color: #444;
    opacity: 0.9;
}

.pub-details {
    flex: 1;
}

.pub-details h4 {
    font-size: 1.1rem;
    margin-bottom: 6px;
    color: var(--text-color) !important;
    line-height: 1.4;
}

.pub-venue {
    margin-top: 0px;
    font-style: italic;
    color: var(--text-muted);
    margin-bottom: 1px;
    font-size: 0.95rem;
}

.pub-authors {
    margin-top: 0px;
    margin-bottom: 10px;
    font-size: 0.95rem;
    color: var(--text-color);
}

.pub-links a {
    display: inline-block;
    margin-right: 8px;
    font-size: 0.85rem;
    border: 1px solid var(--border-color);
    padding: 3px 10px;
    border-radius: 4px;
    background: var(--container-bg);
    color: var(--text-color);
    transition: background 0.2s;
}

.pub-links a:hover {
    background: var(--border-color);
    text-decoration: none;
}

/* 수상 배지 */
.award-badge {
    display: inline-block;
    background-color: #fff8e1;
    color: #d84315;
    font-weight: bold;
    font-style: normal;
    font-size: 0.85rem;
    padding: 2px 8px;
    border-radius: 12px;
    border: 1px solid #ffe0b2;
    margin-left: 8px;
    vertical-align: middle;
}
body.dark-mode .award-badge {
    background-color: #3e2723;
    color: #ffcc80;
    border-color: #5d4037;
}

/* 논문 태그 */
.pub-tag {
    display: inline-block;
    padding: 3px 8px;
    border-radius: 4px;
    color: #fff;
    font-size: 0.75rem;
    font-weight: bold;
    margin-bottom: 6px;
    line-height: 1;
    vertical-align: middle;
}

.tag-red { background-color: var(--tag-red); }
.tag-blue { background-color: var(--tag-blue); }
.tag-green { background-color: var(--tag-green); }
.tag-gray { background-color: var(--tag-gray); }

/* [수정됨] 이미지가 커졌으므로 태그 때문에 이미지를 내리는 코드는 삭제하여 상단 정렬 유지 */
/* .publication-item:has(.pub-tag) .pub-thumb { margin-top: 26px; } */

/* =========================================
   수상 섹션 (Awards)
   ========================================= */
.award-list {
    list-style: none;
    padding: 0;
}

.award-list li {
    display: flex;
    margin-bottom: 15px;
    align-items: flex-start;
}

.award-date {
    font-weight: bold;
    color: var(--text-secondary);
    min-width: 90px;
    margin-right: 15px;
    padding-top: 2px;
}

.award-content {
    flex: 1;
}

.award-content strong {
    display: block;
    color: var(--text-color);
    font-size: 1rem;
    margin-bottom: 2px;
}

.award-content p {
    margin: 0;
    color: var(--text-muted);
    font-size: 0.9rem;
}

/* =========================================
   서비스 섹션 (Services)
   ========================================= */
.service-group {
    margin-bottom: 30px;
}

.service-group h3 {
    font-size: 1.15rem;
    color: var(--text-color);
    margin-top: 40px;
    margin-bottom: 12px;
    padding-left: 10px;
    border-left: 4px solid var(--accent-color);
}

.service-group h3:first-of-type {
    margin-top: 10px;
}

.service-group p {
    margin-bottom: 8px;
    color: var(--text-secondary);
    font-size: 0.95rem;
    line-height: 1.6;
}

/* =========================================
   모바일 반응형
   ========================================= */
@media (max-width: 768px) {
    .container {
        padding: 25px;
        margin: 0;
    }
    
    .profile-header {
        flex-direction: column;
        align-items: center;
        text-align: center;
    }
    
    .link-buttons {
        justify-content: center;
    }

    .publication-item {
        flex-direction: column;
    }
    
    /* 모바일에서는 꽉 차게 보이도록 유지 */
    .pub-thumb img {
        width: 100%;
        max-width: 350px; /* 모바일 최대 크기도 약간 증가 */
        margin-bottom: 10px;
    }

    .edu-header, .work-header {
        flex-direction: column;
        align-items: flex-start;
    }
    .edu-date, .work-date {
        margin-top: 2px;
        margin-bottom: 5px;
    }

    .award-list li {
        flex-direction: column;
        margin-bottom: 20px;
    }
    .award-date {
        margin-bottom: 4px;
        color: var(--accent-color);
    }

    /* 모바일 내비게이션 */
    .nav-links {
        gap: 15px;
        font-size: 0.85rem;
        overflow-x: auto;
        white-space: nowrap;
        padding-bottom: 0;
        -webkit-overflow-scrolling: touch;
    }
    .nav-links::-webkit-scrollbar {
        display: none; 
    }
    .nav-content {
        justify-content: flex-start;
        gap: 15px;
    }
    #theme-toggle {
        margin-left: auto;
    }
}

/* =========================================
   이미지 모달
   ========================================= */
.pub-thumb img {
    cursor: pointer;
    transition: 0.3s;
}

.pub-thumb img:hover {
    opacity: 0.7;
}

.modal {
    display: none; 
    position: fixed; 
    z-index: 2000; /* nav보다 위에 */
    padding-top: 50px; 
    left: 0;
    top: 0;
    width: 100%; 
    height: 100%; 
    overflow: auto; 
    background-color: rgba(0,0,0,0.9);
}

.modal-content {
    margin: auto;
    display: block;
    width: 80%;
    max-width: 900px;
    max-height: 85vh;
    object-fit: contain;
    animation-name: zoom;
    animation-duration: 0.3s;
}

.close {
    position: absolute;
    top: 15px;
    right: 35px;
    color: #f1f1f1;
    font-size: 40px;
    font-weight: bold;
    transition: 0.3s;
    cursor: pointer;
}

.close:hover, .close:focus {
    color: #bbb;
    text-decoration: none;
    cursor: pointer;
}

@keyframes zoom {
    from {transform:scale(0)} 
    to {transform:scale(1)}
}

@media only screen and (max-width: 700px){
    .modal-content {
        width: 100%;
    }
}



/* =========================================
   Research Roadmap (Updated Layout)
   ========================================= */
#research-roadmap {
    text-align: center;
    margin-bottom: 20px;
}

/* [수정 1] 최상단 박스 너비를 아래 카드들과 맞춤 */
.vision-box {
    background: var(--link-btn-bg);
    border: 2px solid var(--accent-color);;
    border-radius: 8px;
    padding: 20px;
    margin: 0 auto 10px auto;
    width: 100%; /* max-width 제거하고 100%로 설정하여 꽉 채움 */
    box-sizing: border-box; /* 패딩 포함 크기 계산 */
    box-shadow: 0 4px 10px var(--shadow-color);
}

.vision-box h3 {
    color: var(--accent-color) !important;
    margin: 0 0 5px 0; 
    font-size: 1.15rem; 
    border: none; 
    padding: 0;
}
.vision-box p { margin: 0; font-size: 0.95rem; color: var(--text-secondary); }

.flow-arrow-vertical { 
    font-size: 1.5rem; 
    color: var(--text-muted); 
    margin: 10px 0; 
}

/* [수정 2] 화살표 중앙 정렬을 위한 설정 */
.flow-arrow-horizontal { 
    display: flex; 
    align-items: center; 
    justify-content: center; 
    font-size: 1.5rem; 
    color: var(--text-muted); 
    padding: 0 10px;
    align-self: center; /* 부모가 stretch여도 화살표는 중앙에 위치 */
}

/* [수정 3] 박스 높이 통일을 위한 stretch 설정 */
.roadmap-container {
    display: flex; 
    justify-content: space-between; 
    align-items: stretch; /* 카드 높이 자동 통일 */
    gap: 10px;
}

/* [수정 4] 박스 너비 강제 통일 */
.roadmap-card {
    flex: 1 1 0; /* 내용물 양과 상관없이 정확히 1:1:1 비율 유지 */
    width: 0;    /* flex 1 1 0과 함께 사용하여 너비 균등 분배 보장 */
    background: var(--container-bg);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    padding: 20px;
    text-align: left;
    box-shadow: 0 2px 8px var(--shadow-color);
    display: flex;
    flex-direction: column; /* 내용물 세로 배치 */
    transition: transform 0.2s;
    position: relative;
}

.roadmap-card:hover { 
    border-color: var(--accent-color); 
    transform: translateY(-3px); 
}

/* --- 이하 기존 스타일 유지 --- */

.step-header {
    display: flex; 
    align-items: center; 
    margin-bottom: 10px; 
    padding-bottom: 10px; 
    border-bottom: 1px solid var(--border-color);
}
.step-num { 
    font-size: 1.5rem; 
    font-weight: 800; 
    color: #868686; 
    margin-right: 10px; 
    line-height: 1; 
}
.roadmap-card h4 { 
    margin: 0; 
    font-size: 1.05rem; 
    color: var(--text-color) !important; 
}

.step-desc { 
    font-size: 0.85rem; 
    color: var(--text-muted); 
    margin-bottom: 12px; 
    line-height: 1.4; 
}

.step-list { list-style: none; padding: 0; margin: 0 0 15px 0; }
.step-list li { 
    font-size: 0.9rem; 
    color: var(--text-secondary); 
    margin-bottom: 4px; 
    padding-left: 12px; 
    position: relative; 
}
.step-list li::before { 
    content: "•"; 
    color: var(--accent-color); 
    font-weight: bold; 
    position: absolute; 
    left: 0; 
}

/* 토글 버튼 */
.paper-toggle-btn {
    width: 100%;
    background-color: var(--link-btn-bg);
    color: var(--text-secondary);
    border: 1px solid var(--border-color);
    padding: 8px 0;
    border-radius: 6px;
    cursor: pointer;
    font-size: 0.85rem;
    font-weight: 600;
    transition: all 0.2s;
    display: flex; 
    align-items: center; 
    justify-content: center; 
    gap: 6px;
    margin-top: auto; /* 하단 고정을 위해 auto margin 사용 */
}

.paper-toggle-btn:hover {
    background-color: var(--border-color);
    color: var(--text-color);
}

.paper-toggle-btn i.icon-arrow { transition: transform 0.3s; }
.paper-toggle-btn.active i.icon-arrow { transform: rotate(180deg); }

/* 숨겨진 리스트 */
.hidden-paper-list {
    display: none;
    margin-top: 10px;
    padding-top: 10px;
    border-top: 1px dashed var(--border-color);
    animation: fadeIn 0.3s ease-in-out;
}
.hidden-paper-list.show { display: block; }

@keyframes fadeIn { 
    from { opacity: 0; transform: translateY(-5px); } 
    to { opacity: 1; transform: translateY(0); } 
}

.hidden-paper-list ul { list-style: none; padding: 0; margin: 0; }
.hidden-paper-list li { margin-bottom: 6px; font-size: 0.85rem; line-height: 1.4; }
.hidden-paper-list a { color: var(--accent-color); text-decoration: none; }
.hidden-paper-list a:hover { text-decoration: underline; }

.card-footer { margin-top: 15px; }
.card-tag { 
    display: inline-block; 
    font-size: 0.75rem; 
    font-weight: bold; 
    color: white; 
    padding: 3px 8px; 
    border-radius: 4px; 
}

/* 다크모드 보정 */
body.dark-mode .roadmap-card { background: #252525; }
body.dark-mode .step-num { color: #444; }

/* 모바일 반응형 */
@media (max-width: 768px) {
    .roadmap-container { flex-direction: column; }
    .flow-arrow-horizontal { 
        transform: rotate(90deg); 
        padding: 10px 0;
        align-self: center; /* 모바일에서도 중앙 정렬 유지 */
    }
    .roadmap-card {
        width: auto; /* 모바일에서는 너비 자동 */
    }
}